A number of difficulties are encountered in the design and construction of such mirrors. In order to satisfy styling requirements, the mirror cases are usually curved in both lateral and vertical planes, and hinging which takes place with most known mirrors tends to scuff the outer (polished) surface of the mirror case, particularly in a forward break-away movement, and further the mirror becomes unstable. One object of this invention is to provide an improvement whereby a mirror case can move through a forward break-away hinging movement, and remain stable during and after this break-away mode. The second object is to remain clear of the mounting bracket until the end of such movement, so that surface damage due to scuffing is unlikely to occur under most break-away conditions.
A third object of the invention is to ensure that the entire forwardly facing surface of the mirror case remains spaced from the bracket upon break-away. Thus, invention there is provided a pivot set outwardly from the mounting bracket of a mirror so that the pivotal axis is away from the bracket. With this arrangement, upon forward break-away the entire forwardly facing surface of the mirror case becomes spaced from the bracket, at least until the end of such movement.
Another problem which is encountered is that, in the past, there has been a requirement for close tolerances, which requirement therefore adds to production costs. This particularly applies when there are four contact points between the mirror case and the mounting bracket, so that two contact points exist during any break-away movement. If the contacts between these elements should be four in number when the mirror housing is in its viewing position, but due to inaccuracy only three contact points are made, the mirror case can be "loose" and vibrate.
In order to ensure that the mirror case will properly reset itself upon the break-away force being released, in an embodiment of the invention the mirror case is retained against the bracket by a spring means, and arranged so that the spring means cause engagement of three spaced points only so that a stable reseating is always available, notwithstanding liberal manufacturing tolerances. The more widely spaced the support points are of course, the more is the stiffness achieved for retaining the mirror in its normal viewing position. Conveniently, a pair of vertically spaced projections (sometimes called stanchions in the trade) at the rearward end of the bracket can be associated with a single contact point at the front end of the bracket, and that contact point can, in the viewing position, be in contact with a ramp surface of the bracket which is however normally obscured from view, but upon hinging in a forward break-away direction, the forward end of the mirror mounting case is moved outwardly away from the bracket by the positioning of the hinge. This also has a further function of reducing the tendency of the mirror casing to vibrate under normal conditions, and enables the liberal tolerance to be used in the manufacture of the parts.
It is important that break-away both in forward and rearward directions should be as stable as possible, and in an embodiment of the invention the pivot can be constituted by a U-shaped wire (or a plastic molding equivalent thereto) projecting outwardly from the mounting bracket and engaged by spaced lugs on the mirror case which inhibit pivotal displacement in a vertical plane during the forward break-away movement. The spaced lugs also function to correctly reposition the mirror mounting case after it has returned from a rearward break-away position.